If your friend is not tech savvy person, i would go with Mint XFCE (maybe Zorin OS Lite). Surely, it will be not as lightweight as Debian, but it will be much more user friendly for him
If he actually feel comfortable tinkering with OS - along side Debian maybe Bodhi Linux or antiX? I tried both of them on one of (in)famous Intel-based netbooks with 512mb RAM and they worked quite well.
So i used to as well. Like you aren’t actively participating so you think that noone will notice that you left
Then, out of nowhere, everyone is asking “Why are you leaving? Stay with us”